the little pocket rockets are great too! but not really waterproof, you can get it wet, but they need to dry. They use the mini gas containers. I get set up for around $50. The burner unit is very small, and both the gas bottle and burner fit inside a small size billy for transport. I will take a photo of it tonight and post it back here. I got the burner from kathmandu on a 50% off sale, but shopping around you can get all types.....i got it for hiking, but will be used for camping weekends on the yak also.
edit....found this in a catalouge I have, mine is similar, different brand, the cooker folds up nice and small and replacement gas is about $5 per can, they have bigger sizes too, and I use a fry pan on mine too, mainly the billy though.